CN214666615U

CN214666615U - Inheritance large-deformation resistance strain gauge test structure

Info

Publication number: CN214666615U
Application number: CN202120500041.2U
Authority: CN
Inventors: 叶晓明; 陈柏林; 郭琪; 傅翔
Original assignee: Chongqing Daheng Engineering Design Co Ltd
Current assignee: Chongqing Daheng Engineering Design Co Ltd
Priority date: 2021-03-09
Filing date: 2021-03-09
Publication date: 2021-11-09
Anticipated expiration: 2031-03-09

Abstract

The utility model provides a succession nature large deformation resistance foil gage test structure establishes two consolidation regions at test region L both ends, with a plurality of resistance foil gages Y_iBoth ends are fixedly connected on the test object; within the test zone L, each resistive strain gage Y_iHas a length of L_i‑1＜L_i≤L_i‑1(1+ δ) (i = 2.. i.. n.) δ represents the effective test strain range of the resistance strain gage. The utility model discloses extend resistance strain gauge small deformation test advantage to the large deformation test field, can improve the large deformation and detect the precision, extend the large deformation detection range, have fine application market prospect.

Description

Inheritance large-deformation resistance strain gauge test structure

Technical Field

The utility model belongs to the technical field of the deformation test, concretely relates to succession big deformation resistance foil gage test structure.

Background

The resistance strain gauge testing technology has been developed for decades and is widely applied to engineering deformation detection, and is one of the most common deformation detection means used at present.

The resistance strain gauge is a sheet-shaped deformation sensing element, the main material is a very thin constantan wire, and the working principle is as follows: after the deformation, the constantan wire is elongated, the cross section area is reduced, and the resistance value is increased; deformation data is obtained by detecting a change in the resistance value according to the relationship between the resistance value and the deformation. The manufacturer bends the constantan wire into a certain shape and then concretes the constantan wire into a sheet-shaped sensing element by using a high molecular material, and then carries out unified calibration and batch production. The resistance strain gauge has the characteristics of simple and clear working principle, low cost, easiness in implementation, high precision and the like, and is generally applied. However, the resistance strain gauge is limited by the deformability of the constantan wire, when the deformation is too large, the constantan wire is broken, and the effective strain range is usually about 1.0%. For large deformation engineering such as structural engineering and geotechnical engineering which utilize plastic deformation, the range of the resistance strain gauge is obviously insufficient, so that the resistance strain gauge cannot be applied, which is a technical problem to be solved urgently in the large deformation detection at present.

SUMMERY OF THE UTILITY MODEL

To the problem that exists among the background art, the utility model aims to provide a big deformation resistance foil gage test structure of inheritance and test method.

In order to achieve the above purpose, the present invention adopts the following technical solution.

The utility model provides a big deformation resistance foil gage test structure of inheritance which characterized in that: arranging a plurality of resistance strain gauges Y with different lengths at test points_iEach resistance strain gauge is externally connected with a test instrument 3 through a lead 2; two bonding regions 1 are arranged at two ends of the test region L, and a resistance strain gauge Y is arranged_iBoth ends of which are fixed on the test object 4, or a resistance strain gauge Y_iIs fixed on the test carrier 5, and the test carrier 5 is fixed on the test object 4; within the test zone L, the first oneResistance strain gauge Y₁Has a length of L₁= L, other resistance strain gage Y_iHas a length of L_i-1＜L_i≤L_i-1(1+ delta) (i =2,.. i.,. n), i represents the number of the resistance strain gauges, n is more than or equal to 2, and delta represents the effective testing strain capacity of the resistance strain gauges and is provided by a manufacturer.

Further, each resistance strain gauge Y_iThere are common consolidation areas 1 and the initial clear spacing between consolidation areas 1 is L.

Still further, the resistance strain gauge Y is determined according to the maximum value of the test deformation_iThe number n of (2).

Further, the material, shape, and size of the test carrier 5 are determined according to the test object and the environment.

The test method based on the inheritance large-deformation resistance strain gauge test structure comprises the following steps:

a resistance strain gauge Y_iThe group is fixed on the test object 4 or fixed on the test object 4 through the test carrier 5;

resistance strain gauge Y_iThe testing instrument 3 is externally connected through a lead 2;

in the deformation test process, firstly, a first resistance strain gauge Y is passed₁Testing the deformation amount; when the first resistance strain gauge Y₁In failure, the second resistance strain gauge Y₂Entering a test state; when the second resistance strain gauge Y₂In failure, the third resistance strain gauge Y₃Entering a test state; … …, respectively; repeating the steps until the large deformation test is completed;

the deformation test results are: strain gauge Y_iData overlay Y_iY at the same time point as the starting point_i-1End data.

Has the advantages that:

(1) the large deformation of a test object can be tested by adopting the test precision of the small deformation magnitude based on the resistance strain gauge, the situation that the traditional large deformation test precision is far smaller than the small deformation test precision is fundamentally solved, the method belongs to a breakthrough of the traditional large deformation detection technology, and the prospect is wide;

(2) the device can test large deformation items which cannot be tested by the existing resistance strain gauge testing technology, and in principle, the deformation of almost all materials can be tested by adopting the utility model as long as necessary protection measures are taken, so that more possibilities and new directions are provided for the development of the deformation technology;

(3) the utility model provides a big deformation resistance foil gage test structure of inheritance and method have simple structure, stability good, but detect the precision high, batch production, structure cost and implementation cost low grade advantage, have very big application prospect.

Drawings

FIG. 1 is a schematic top view of a test structure of a high-deformation-resistance strain gage in example 1;

FIG. 2 is a schematic front view of a test structure of a inherited large deformation resistance strain gauge in example 1;

FIG. 3 is a schematic diagram of a combined resistance strain gage of the inherited large deformation resistance strain gage test structure of example 2;

in the figure: 1-a resistance strain gauge consolidation region; 2-a wire; 3-testing the instrument; 4-test object; 5-test carrier; l-test area (length); y is₁、Y₂、Y₃-a first, a second and a third resistive strain gauge; l is₁、L₂、L₃-the first, second and third resistance strain gage lengths of the test zone range; p is the tension of the end of the test structure; i-resistance strain gauge number.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The described embodiments are only some, but not all embodiments of the invention. In the description of the present invention, it should be noted that the resistance strain gauge in the embodiment shows only 3 pieces (Y)₁、Y_i、Y_n) The sequential relationship of the test resistance strain gauges is merely illustrated, and is not to be construed as limiting the present invention.

Example 1

The test object 4 is a tension member, tension P acts on two ends, and large deformation in the range of 3.0% of middle strain in the tension process of the test member is needed. Because the maximum strain of the traditional resistance strain gage test is 1.0 percent, the utility model discloses the method can only be used to test.

The effective test dependent variable maximum value of the test resistance foil gage product of market purchase is δ =1.0%, according to the utility model discloses a succession nature principle can arrange 3 resistance foil gages, and its effective test dependent variable is 3x1.0% =3.0%, can satisfy this detection requirement.

To facilitate accurate control of the resistive strain gage length L_iA test method in which the resistance strain gauge is first fixed to the test carrier 5 in the chamber and then the test carrier 5 is fixed to the test object 4 is adopted, see fig. 1 and 2.

Consolidation of strain gauges on test carrier 5:

1. the test carrier 5 selects a high-molecular sheet material meeting the requirement of deformation ductility;

2. the length of the test area is L =20mm, the effective test strain delta =1.0% of the resistance strain gauge, and L is within the range of the length L of the test area₁=L=20mm、L₂=L₁（1+δ）=20（1+0.01）=20.2mm、L₃=L₂（1+δ）=20.2（1+0.01）=20.402mm；

3. Uniformly fixing the resistance strain gauge on the test carrier 5 by using an adhesive, wherein the resistance strain gauge Y₁The other strain gauges are placed in a straight manner and are placed in an upward convex manner, see the three drawings on the right side in fig. 2 (a);

4. the length L of the resistance strain gauge is noted during manufacturing_iThe variation is controlled within the test zone length L.

The implementation steps are as follows:

1. the pre-consolidated test carrier 5 containing three resistance strain gauges is consolidated on the test point of a test object 4 by using a binding agent, and the resistance strain gauges are connected to a test instrument 3 by using a lead 2;

2. selecting a plurality of fixed points according to field conditions, fixing the lead 2 well, preventing the tension member from deforming to break the lead, and taking protective measures for the resistance strain gauge and the lead to prevent damage;

3. starting a test instrument, checking whether the circuits are communicated or not, detecting abnormal phenomena such as damage and the like, and reading test initial data;

4. under the working test condition, applying an acting force P on the tension member, and simultaneously recording deformation data of the resistance strain gauge until the deformation reaches a required detection value;

5. the data acquisition mode is as follows: the first stage being modified by using Y₁The second stage adopts Y for deformation₂Data overlay Y of₂Y at the same time point as the starting point₁End data, third stage variant with Y₃Data overlay Y of₃Y at the same time point as the starting point₂End data.

The utility model discloses the test inheritance principle as follows:

1. when the first stage of the component is stressed, the first resistance strain gauge Y₁Is arranged in a straight line, and the deformation of the component can be detected, as shown in the three figures at the right side of (a) in FIG. 2;

2. at the end stage of the first stage of stress of the component, a first resistance strain gauge Y₁The deformation gradually enters the edge of the detection range, and at the moment, the second resistance strain gauge Y₂Gradually straightening, and entering a deformation detection preparation stage;

3. when the second stage of the member is stressed, the first resistance strain gauge Y₁The deformation enters a failure stage, which is characterized by irregular deformation or tensile breakage, and at the moment, the second resistance strain gauge Y₂Entering a deformation detection working state to complete first inheritance, wherein the three graphs on the right side of 2 (b) in the figure;

4. according to the principle of 1, 2 and 3, when the third stage of the component is stressed, the third resistance strain gauge Y₃Entering a deformation detection working state to complete second inheritance, wherein the graph is shown as three graphs on the right side of 2 (c);

5. according to the principle, the method can carry out inheritance for n-1 times so as to meet various large deformation detections.

In addition, according to the detection precision requirement, each inheritance can be partially overlapped. Namely: last stage resistance strain gauge Y_iBefore exiting from the operation, go downFirst-level detection optical fiber Y_i+1And entering a working state in advance, adopting stable and reasonable values of two-stage test data according to the test time node, and then overlapping.

Example 2

The detection content of example 1 was completed using a finished product of a combined type inherited large deformation resistance strain gauge.

Various combined type inheritance large-deformation resistance strain gauges are produced in batches by resistance strain gauge manufacturers, please refer to fig. 3.

During detection, a combined type inheritance large-deformation resistance strain gauge finished product meeting specific requirements is directly purchased and fixedly connected to a detection point, and then detection is carried out according to the steps of the embodiment 1.

Claims

1. The utility model provides a big deformation resistance foil gage test structure of inheritance which characterized in that: arranging a plurality of resistance strain gauges Y with different lengths at test points_iEach resistance strain gauge is externally connected with a test instrument (3) through a lead (2); two fixing regions (1) are arranged at two ends of the test region L, and the resistance strain gauge Y_iBoth ends are fixed on the test object (4) or the resistance strain gauge Y_iIs fixed on the test carrier (5), and the test carrier (5) is fixed on the test object (4); within the test zone L, a first resistive strain gage Y₁Has a length of L₁= L, other resistance strain gage Y_iHas a length of L_i-1＜L_i≤L_i-1(1+ delta) (i =2,.. i.,. n), i represents the resistance strain gauge number, n ≧ 2 is the strain gauge number, and delta represents the effective test strain capacity of the resistance strain gauge.

2. The inherited large deformation resistance strain gage test structure of claim 1, wherein: each resistance strain gauge Y_iThere are common consolidation regions (1), with an initial net spacing between consolidation regions (1) of L.